What Causes Persistent Bleeding Inspite Of Taking Medroxyprogesterone?

I started taking the birth control pills seasonale to stop my period because I have endometriosis, pcos, and a fibroid in my uterus.I started it on January 26 2015, things were fine and then I started bleeding on February 20 with bad cramping and blood clots. Went to emergency on February 25 and was prescribed medroxy 10 mg pills for seven days. I ve been bleeding for none days three of which I ve been on the medroxy and I ve had no improvement of bleeding. I m starting to get worried and I know my ironic low. Someone please help